1. Field of the Invention
The present invention relates to a heating apparatus for hyperthermia and, more particularly, to a heating apparatus for hyperthermia which deteriorates the regenerative functions of cancerous cells by heating them with electromagnetic waves, thereby liquidating these cancerous cells.
2. Description of the Prior Art
In recent years, hyperthermia has been given wide attention and papers have been written on hyperthermia, a therapy which deteriorates the regenerative functions of cancerous cells and thereby liquidates significant portions of them by applying heat of approximately 43.degree. C. for one or two hours and repeating the treatment at certain intervals.(MICROWAVES.October, 1976).
There are two kinds of hyperthermia therapy: general and local heating methods. Three methods have been proposed for local heating: one utilizes electromagnetic waves, the second uses electric conduction and the third uses ultrasonic waves.
Researchers have concluded that the optimum temperature for attacking cancerous cells is 43.degree. C. or thereabouts. Temperatures below this will weaken the effects and temperatures above this will damage normal cells. Hyperthermia aims at liquidating cancerous cells without heating normal cells by maintaining the temperature in a confined narrow range.
However, it has been quite difficult when utilizing conventional means to keep the temperature of cancerous cells at approximately 43.degree. C. for one or two hours due to the peculiar functions of a living body. In particular, heating by electromagnetic waves has been put aside for a long time because a significant portion of the electromagnetic waves is absorbed by the body surface and this method is thus unfit for heating regions deep within the body. In view of the above-described circumstances, the inventors of the present invention have previously proposed a heating apparatus for hyperthermia utilizing electromagnetic waves which is provided with a function which enables accurate control of the temperature of a given heated region in a living body such that this temperature is maintained at a predetermined value over a certain period of time.
Hyperthermia takes a relatively long period of time (about one hour) for a single treatment and requires that this treatment be repeated periodically, which fact involves an unfavorably long overall treatment time. In consequence, treating a large number of patients at the same time requires a correspondingly large number of devices and unfavorably increases the cost of installing equipment for treatment.
Subject matter related to the present application is disclosed in the following co-pending applications, each of which is assigned to the assignee of the present invention: application Ser. No. 878,327 filed June 25, 1986; application Ser. No. 878,328 filed June 25, 1986; and application Ser. No. 878,329 filed June 25, 1986; and application Ser. No. 757,850 filed July 22, 1985.